Life Healthcare says its southern African operations have been targeted through an attack on its IT systems.
In a statement on Tuesday, the group said it acted immediately after becoming aware of the hack and took its systems offline.
The extent to which sensitive data has been exposed is not yet known the company says.
They say patient care has not been impacted as hospitals and administrative offices have switched over to backup manual processing systems.
Pieter Van der Westhuizen, Acting Group CEO said: “We apologise for any frustration, delay, or distress this criminal act has caused to our patients, doctors, employees, funders and other stakeholders. We thank them for their understanding, support and patience as we resolve this matter.
“Patient care remains our key priority. We are deeply disappointed and saddened that criminals would attack our facilities during such a time, when we are all working tirelessly and collectively to fight the Covid-19 pandemic.
“We regret that the disruption caused by this incident may cause our patients some frustration, in what is already a trying time. We recognise and thank our employees, doctors and service providers for their dedication, and the professionalism they have shown by quickly adopting our manual backup systems.”
Investigations are continuing into the data breach.